混凝土浇筑的沼气池,批灰层的强度应养护到()方能进行检查。
A、70%
B、60%
C、50%
D、40%
参考答案:A
在Windows 2003下,当微机新安装了一台打印机时,使用前必须为该打印机安装(),然后才能使用。
A.序列号
B.驱动程序
C.保护卡
D.文件夹
Monetarists believe that:()
A. shifts in aggregate demand arise from changes in expectations.
B. monetary policy has a significant impact on aggregate demand.
C. money wages tend to adjust quickly when aggregate supply and aggregate demand are in disequilibrium.